Build & Compile

Strategies for building code and resolving dependency issues.

Build System Detection

Check for build files in order:

• Makefile → make (read it first to understand targets)
• CMakeLists.txt → cmake -B build && cmake --build build
• pyproject.toml / setup.py → pip install -e .
• package.json → npm install && npm run build
• Cargo.toml → cargo build --release
• go.mod → go build ./...
• No build system → compile directly (gcc, g++, rustc, etc.)

Compilation Strategies

C/C++

• Always read the Makefile/CMakeLists first
• Common flags: -O2 -Wall -lm -lpthread
• Missing headers → apt-get install lib<name>-dev
• Linking errors → check library order (dependencies last: -lfoo -lbar -lm)

Python

• Use virtual environments when possible
• pip install -e . for editable installs
• Missing modules → check requirements.txt, pyproject.toml
• Version conflicts → read the actual error, pin versions

Multi-language projects

• Build dependencies first (C libraries before Python bindings)
• Check for Cython, SWIG, or FFI bridges
• Environment variables often needed: LD_LIBRARY_PATH, PYTHONPATH

Dependency Resolution

1. Read the FULL error message — the missing dependency is usually named
2. Search for the package: apt-cache search <name>, pip search <name>
3. Install the minimum needed — don't install everything
4. If a package is unavailable, check for alternatives or build from source

Common Build Failures

Error	Likely Cause	Fix
fatal error: foo.h: No such file	Missing dev headers	apt-get install libfoo-dev
undefined reference to	Missing library at link time	Add -lfoo flag
No module named 'foo'	Missing Python package	pip install foo
command not found: make	Build tools missing	apt-get install build-essential
version 'GLIBC_X.Y' not found	Binary built for newer system	Rebuild from source